Chaeles e



(No Model.) g C. E. SORIBNER.

CLEARING OUT ANNUNOIATOR. Patented May 15, 1888.

'"llllllllll "lllllllllll UNITED STATES PATENT CHARLES E. SCRIBNER, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE \VESTERN ELECTRIC COMPANY, OF SAME PLACE.

CLEARING-OUT ANNUNCIATOR.

SPECIFICATION forming part of Letters Patent No. 383,015, dated May 15, L888. Application filed December 2'7, 1886. Renewed November 21, 1987. Serial No. 255,772. (No model.)

To all whom it may concern: 7

Be it known that 1, CHARLES E. SORIBNER, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Clearing-Out Annunciators for Telephone-Exchanges, (Case 125,) of which the following is a full, clear, concise, and exact description, reference being had to the ac- IO companying drawings, forming a part of this specification.

My invention relates to clearingout annunciators for telephone-exchanges; andit has for its object the transmission of two signals upon a single annuneiator.

In certain telephone exchanges it is desirable that the subscribers should call each other after the central-offiee operator has switched their lines into connection. When this sys- 2o tern is employed, it is also desirable that the subscribers, after the termination of a conversation shall be able to signal the central office.

My invention provides for a clearingout signal at the central ofice which is not actuated when one subscriber calls another, but

which may be actuated at the will of the subscriber.

My invention is illustrated in the aecompanying drawings, in which-- Figure 1 is a side elevation of my annunciator. Fig. 2 is a rear elevation thereof, showing a portion of the neutral armature broken away. Fig. 3 is a diagrammatic view of the electromagnets and circuits of same. 5 Like parts are indicated by similar letters of reference throughout the different figures.

Referring to Fig. 1, a is a plate, upon the rear of which are mounted electro-magnets b and 0, andupon the front of which is mounted 40 the shutter or flap d. The neutral armature e, pivoted at f, is opposed to the poles of the electro-magnet b. An armature-lever, g, is carried by armature c, and is provided at its free end with a double hook, h, which engages with and normally holds up shutter d. Two

motions of armature 6 toward the pole of electro-1nagnet b are required to release the shutter d, the first motion permitting the shut ter to start and fall against the upper catch of the hook, and dropping to engage the second notch below, another motion of the armaturelever releasing the shutter and permitting it to fall. Polar extensions 2', from the poles of the electro-magnet b, are provided with and are opposed by a centrally-pivoted polarized armature, It. This armature is polarized by permanent magnet Z. Thepoles of electro-magnet 0 are extended through the frame plate a, and are so presented to the shutter d,which is of iron, as to hold the shutter up by the attraction for it when the current traverses the coils of the electro-magnet.

Referring to Fig. 3, the circuit may be traced through the electro-magnets b and 0 and out.

A shunt or short circuit may be traced around 6 electro magnet 0, beginning at pointm, thence to polarized armature k, and thence through contact-point n to the cores of the electromag net b, and thence to point 0. This shunt. or short circuit prevents current from traversing 7o coils 0 when polarized armature 7c is in con tact with either of the contact-points a of the pole-pieces of magnet 12. Polarized armature It will rock or vibrate upon its pivot, alternately striking one pole or the other of magnet I), when an alternating current is traversing the coils of magnet b. lVhen currents are not traversing the coils of magnet 12, armature it sticks to one-pole or the other of said magnet Z), because of its magnetism acquired of its permanent magnet Z. Currents of one polarity sent through magnet 11 will hold the armature 7a to one pole or the other accordingly as the current is in one direction or the other. New tral armature e is attracted by the electro mag- 8 5 net I) when currents traverse its coils regardless of the direction of the current.

Now, suppose an alternating current to be traversing the coils of electro-magnet l). Armature in vibrates with the alternations from 0 one pole to the other, and during the period of its vibration the shuut-circuitn to it to pole of magnet I) to 0 is broken. Magnet 0 thus becomes energized and its poles attract iron shutter cl and prevent it from falling, al- 5 though armaturelever g and its hook it vibrate, tending to release the shutter. Theimpulses through electro-magnet 0 occur with each vibration of armature k, and although short are of sufficient strength to retain the I00 shutter 01 and prevent it from falling. Ii'pul sations of current in one direction are transmitted through electro magnet b, armature 75 does not vibrate, but remains in contact with one pole of said magnet, thus shunting out of circuit electro-magnet 0. Neutral armature 6, however, is attracted, and two impulses of current through magnet 11 will cause the armature eto raise hook h twice, thus releasing the shutter d,which falls, as it is not attracted by the poles of the magnet c.

The object of the double detcnt h is to prevent shutter d from fallingin case thefirstinr pulse of an alternating current should be in a direction to hold armature 7c upon the pole against which it already chanced to rest. If there were but a single 'detent, the shutter would fall upon the first impulse, as the magnet 0 would continue shunted during that impulse. WVith the double detent two impulses are necessary to release the shutter, and if an alternating current be sent armature It must vibrate at the second impulse, letting magnet 0 into the circuit, and even though the shutter has moved to the second detent it will not have passed out of the reach of the attraction of magnet c and will be drawn to its poles. Now, therefore, if an alternating current be sent over a line in the circuit of which my annunciator is included, the shutter will not drop and no signal willbegiven. If impulses of one polarity be sent upon theline, the shutter will drop.

The ordinary polarized magneto-bells and generators supplied to subscribers stations of a telephone-exchange are arranged to send alternating currents, and with my annunciator may be used by one subscriber for calling another wilhout dropping the shutter at the central office. A simple battery placed at each subscribersstation, with switching devices for introducing it into the circuit of the subscribers line, may be used for transmitting impulses of one polarity. WVhen such impulses are transmitted, the shutter will fall at the central oftiee, and the other subscriber's bell, although in circuit, will not ring, it being a polarized bell.

Thus after a connection any subscriber can call the central office without calling the other subscriber, or he may call the othersubscriber without calling the central office.

Having thus described myinvention, Iclaim as new and desire to secure by Letters Patent- 1. In an annunciator,an eleetro-magnet with two armatures, one of said arlnatures being polarized,the other armature being neutral, in combination with an electro-magnet normally shunted out of circuit by the said polarized armature, and a shutter normally held by the armature lever of neutral armature, said shutter being opposed to the poles of the normallyshunted magnet, whereby alternating currents traversing the annunciator will prevent the shutter from falling.

2. An electric annunciator provided with two armatures, one of said armatures being polarized and the other neutral, the neutral armature being extended and provided with a catch for holding up the annunciator-shutter, said shutter being connected with the armature of another electro-magnet,in combination with ci rcuit-connections,whereby astraight current through the coils of the annunciator operates the neutral armature thereof to cause theshutter to fall, the coils of the magnet, of which the shutter serves as an armature, being shunted out by the polarized armature.

3. In an electric annunciator, the combination,with the neutral armature connected with the double detent, of theshutter normally sup ported thereby, said shutter being of iron and placed so as to be acted upon by an electroinagnet, c, the polarized armature of the annunciator, and circuit-eonnections,whereby a straight current sent through the elcctro-magnet of the an nunciator is shunted from electromagnet 0, while the double det'ent is operated to permit the shutter to fall, substantially as described.

4. An electric annunciator consisting of an electro-magnet and two armatu res, one of which is polarized and the other neutral, the neutral armature being connected with adouble detent which serves to retain an iron shutter, in combination with an electro-magnet, 0, presented to said shutter,and eircuit'connections, whereby current of one polarity causes the detent to vibrate and release the shutter, magnet 0 being at the time shunted out by the polarized armature.

5. The combination,with an electro'n'iagnet normally shunted out of circuit by the polarized armature of the electro-magnet of an annunciator, of the neutral armature of said electric annunciator extended to form a double detent, the iron shutter supported thereby, said shutter being presented to the poles of the normally-shunted electro-magnet, whereby the shutteris retained in position or allowed to fall, according as current of one polarity or current in reversals is sent through the annunciator.

name this 16th day of November, A. D. 1886.

' CHARLES E. SORIBNER.

Witnesses:

GEORGE P. BARTON, W M. M. GILLER.

In witness whereof I hereunto subscribe my 

